Variation by stage in the effects of prediagnosis weight loss on mortality in a prospective cohort of esophageal cancer patients.

Cancer cachexia is increasingly recognized as a poor prognostic marker for various tumor types. Weight loss in esophageal cancer is multifactorial, as patients with bulky tumors also have reduced ability to eat. We aimed to investigate the relationship between prediagnosis weight loss and mortality in esophageal cancer and to determine whether these associations vary with tumor stage. We conducted a prospective cohort study of esophageal cancer patients at two tertiary centers. We recorded baseline patient characteristics including medications, smoking, body mass index, and weight loss in the year prior to diagnosis, and collected data on treatment and outcomes. We used Cox regression modeling to determine the associations between percent weight loss and outcomes. The main outcome of interest was all-cause mortality; secondary endpoints were esophageal cancer-specific mortality and development of metastases. We enrolled 134 subjects, the majority of whom had adenocarcinoma (82.1%); median percent weight loss was 4.7% (IQR: 0%-10.9%). Increasing percent weight loss was not associated with all-cause mortality (ptrend = 0.36). However, there was evidence of significant interaction by tumor stage (p = 0.02). There was a strong and significant association between prediagnosis weight loss and mortality in patients with T stages 1 or 2 (adjusted HR 8.26 for highest versus lowest tertile, 95%CI 1.11-61.5, ptrend = 0.03) but not for T stages 3 or 4 (ptrend = 0.32). Body mass index one year prior to diagnosis was not associated with mortality. Prediagnosis weight loss was associated with increased all-cause mortality only in patients with early stage esophageal cancer. This suggests that tumor-related cachexia can occur early in esophageal cancer and represents a poor prognostic marker.